Sensitized material holder or carrier for photographic synchronizer testing equipment



y 1944. J. A. SPRAGUE 2,353,897

SENSITIZED MATERIAL HOLDER OR CARRIER FOR PHOTOGRAPHIG SYNCHRONIZER TESTING EQUIPMENT Original Filed Sept. 50 1942 5 Sheets-Sheet l v as ,8? 69 007 7 -03 36:

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A. SPRAGUE HIC 5 Sheets-Sheet 2 EB OR CARRIER FOR PHOTOGRAP SYNCHRONIZER TESTING EQUIPMENT Original Filed Sept. 50 1942 SENSITIZED MATERIAL HOLD mw a 6B R mm m mm mNR July 18, 1944.

July 18, 1944. SPRAGUE 2,353,897

SENSITIZED MATERIAL HOLDER OR CARRIER FOR PHOTOGRAPHIC SYNCHRONIZER TESTING EQUIPMENT Original Filed Sept. 30 1942 5 SheetsSheet 3 83- GREEN 83 RED 'Invenior: fosepi z/Ajpif' ape. yX MQIHIJ/M fig;

y 1944. J. A. SPRAGUE 2,353,897

SENSITIZED MATERIAL HOLDER OR CARRIER FOR PHOTOGRAPHIC SYNCHRONIZER TESTING EQUIPMENT Original Filed Sept. 50 1942 5 Sheets-Sheet 4 0 1 I a 47 5 88 p39 3 /o/ we Inveni/or: iToseph A. Sprague,

J. A. SPRAGUE 2,353,897

ER OR CARRIER FOR PHOTOGRAPHIC July 18, 1944.

SENSITIZED MATERIAL HOLD SYNCHRONIZER TESTING EQUIPMENT Original Filed Sept. 30 1942 5 Sheets-Sheet 5 fllllllllli ray 4.?

Patented July 18, 1944 SENSITIZED MATERIAL HOLDER 03 CAR- man FOB PHOTOGRAPH) SYNCHBO- mm TESTING EQUIPMENT Joseph A. 8m Boneoye Falls, N. Y., assignor to The Foimer Grade: Corporation, N. Y., a corporation of Delaware Rochester,

Original application September :0, 1942, Serial Divided anllthil application September 2, 1948, Serial No. 500.910

izoaua.

This application is a division of my co-pending application Ser. No. 460,313, filed September 30, 1942, for Photographic synchronizer testing equipment.

This invention relates to a sensitized material holder or carrier for a photographic synchronizer testing equipment.

In order that the principle of the invention may be readily understood, I have disclosed a single embodiment of my invention in the accompanying drawings, wherein Fig. 1 is a front elevation of the synchronizer tester claimed in said application, in condition for making a record test, with the horizontal member in transverse section, showing the shutter and lens board with the magnetic tripper attached thereto, the sensitized material holder or carrier herein claimed being shown in dotted lines;

Fig. 2 is a rear elevation of Fig. 1, showing the position of the said sensitized material holder or carrier prior to making a record test, the mechanism being in condition for making the same;

Fig. 3 is a view similar to Fig. 1, but on an enlarged scale, showing the sensitized material holder or carrier in dotted lines in position for shutter operation;

Fig. 4 is a partial horizontal section through Fig. 3 on the line 4-4 thereof, showing the parts of the sensitized material holder or carrier as positioned when a record test is being made;

Fig. 5 is a fragmentary front elevation of the light valve or gate used when selecting the type of test to be made, i. e. a visual test or a record test, the light valve being in position for making a record test;

Fig. 6 is a fragmentary view of a developed photographic sheet or chart showing both the trace produced by the photofiash lamp and the trace produced through the shutter;

Fig. 7 is a fragmentary, rear view detail of the sensitized material holder or carrier, showing the several openings used in checking the shutter by the visual test;

Fig. 8 is a fragmentary view of one of the dark slides used in said holder or carrier when'making visual tests, and showing the position of the filters thereon;

Fig. 9 is a fragmentary view of the synchronizer tester vertical frame, showing the means for supporting the lens board, the gate or light valve being set in condition for making a visual test;

Fig. 10 is a view similar to Fig. 1, but showing the sensitized material holder or carrier in dotted lines, in position for making a visual test;

Fig. 11 is a view similar to Fig. 2, but showing the ilashlamp in the position wherein the synchronizer testing equipment is in condition for making a visual test;

Fig. 12 is a view similar to Fig. 3, but showing the mechanism in condition for making a visual test, the shutter being in the open condition so as more clearly to show the structure thereof; and

Fig. 13 is a section through Fig. 10, showing the position of the dark slide of said holder or carrier when the parts are in position for making a visual test.

When a flash gun or photoflash equipment is installed on a camera, it is necessary to have some means for checking the synchronization of the peak of the flash with the opening of the photographic shutter. It is also necessary to have some such equipment for checking the synchronization after any of the parts have been removed for repairs or for any other reason. There have been developed for use in wellequipped laboratories, very elaborate means for checking such equipments, but therehas long been need for a simple equipment that could be used in a dark room in the field and that would give a quick visual check upon the performance of the apparatus, and if necessary make a photographic record of the performance of the camera shutter when equipped with a flash synchronizing mechanism. My invention herein claimed relates to a sensitized material holder or carrier to be used in the herein disclosed equipment that does both things in a highly satisfactory manner.

The object of my invention is to provide a simple sensitized material holder that can be loaded with a sheet of sensitized material for providing a permanent photographic record.

Referring first to Figs. 1 and 2, the structure constituting the testing equipment using my herein claimed invention is mounted on a table or other suitable support, upon which is positioned in a face-to-face relation therewith (being secured thereto if desired) a base supporting member 2!, preferably of wood, shown as rectangular in cross section, and to which is attached a vertical support member 22 preferably of sheet metal and attached to the said base supporting member 2| by screws 23, 23, shown in Figs. 2 and 11.

As indicating the use of the disclosed embodiment of the testing equipment-I have shown as an example of a synchronizer that may be tested in the testing equipment, the synchronizer that is disclosed in the patent to Oscar Steiner, No. 2,329,011, dated September '1, 1943, but my equipment is intended for use in testing synchronizers differing widely in construction. There is provided with the equipment a suitable battery case with flashlamp and reflector.

A lens board receiver 2| is attached to the vertical support member 22 by screws 22, 22, be-' ing most clearly shown in Fig. 3. As there indicated, and also in Figs, 1, 2, etc., it has fitted thereinto a lens board v20 whereon is mounted a shutter 2! having a lens 22, such lens board 2| being held in position by retaining springs 22, 22 pivoted to the vertical support member 22 by screws 24, 24. Also mounted upon the said vertical support member 22 is an electrical switch 35 held in position by an insulating strip II to which the switch 25 is secured by screws 21, 21, the said insulating strip 28 being itself held to the vertical support member 22 by screws ll, 38, shown in Figs. 2 and 11. The said switch 35 is provided with the usual contact screws, to which are attached a pair of bus-bars 40, 40 terminating under the heads of screws 21, 21, which pass through the body of the switch 25 and serve as contacts to which are attached suitable wires including a cable 41 consisting of wires 48, 49, provided with an electrical plug 50 fitted into a to-and-fro or axially movable element SI of an electromagnetic tripper 52 held to the lens board 30 by a tripper bracket 53 itself attached to said lens board by screws 54, 54, all as best shown in Figs. 1, 3, 12 and 13, collectively.

Referring particularly to Figs. 1, 2' and 4, the said electromagnetic tripper 52 is in mechanical connection with a shutter release arm 58 by means of a connecting link 56 or in any other suitable or desired manner. The shutter Ii is provided with the usual set lever 51. The vertical support member 22 is desirably of a channel formation, as shown most clearly in Fig. 4, and it is of a shape and construction to receive the sensitized material holder or carrier 58 of my present invention (shown in dotted lines in Fig, 1 and in solid lines in Fig. 2) which contains sensitized material 58a. Hereinafter the part 58 is referred to as the holder, merely for convenience of description.

The structure and proportions of the channel formation of the vertical support member 22 with respect to the sensitized material holder 5! are such that the said holder 58 will drop freely in a vertical direction when released by the means now to be described, constituting a part of the testing equipment. In order to maintain the said holder 58 in its initial position before the dropping thereof, I provide any suitable means, but for the purpose I have herein represented latching means consisting of a lever 59 (shown in Figs. 1 and having a release pad 60 for manual manipulation, said lever being secured to the vertical support member 22 in a horizontal position on a bracket 6|, itself held to the vertical support member 22 by means of screws 62, 82 (Fig. 1). The said lever 59 is itself attached to the bracket Si by a shoulder screw 63, being free to pivot thereon, and is provided with a laterally extending finger (not shown). The purpose of the said finger is to engage a ledge 85 of the sensitized material holder 58 (best shown in Figs. 2, 10 and 11), which is formed by providing an opening in the said holder 52. The vertical support member 22 is provided with a suitable opensaid finger of lever II from the ledge 08 of the holder ll,'the latter is permitted to drop vertically.

The switch ll (best shown in Figs. 1 and 3) is provided with an operating arm 01. The said switch is desirably a standard switch obtained on .the open market and is preferably of the type known as Microswitch and the operating arm '1 is a part of the said switch as purchased.

The vertical support member 22 is provided with a suitable cut-out or opening to allow the arm ll to extend through one of the side walls of the vertical support member 22, so that the switch operating arm 61 extends into the path of the sensitized material holder I8 when the latter is permitted to drop in the vertical support member 22. This action is best indicated in Fig. 3, wherein the switch operating arm 01 is shown depressed as the sensitized material holder 82 passes said operating arm. When the said sensitized holder 58 reaches the position shown in Fig. 3, the said switch operating arm 61 is moved by the said holder 58 in the left hand direction viewing said figure, thus operating the switch 35 and closing the contacts thereof. This movement completes the circuit, thus causing the flash-lamp to be ignited and the electromagnetic tripper 52 to be operated, thereby operating the camera shutter 3| just as such shutter would have been operated had the switch of the battery case been operated in the usual manner in taking a photograph by the camera, instead of by operating the switch 35 of the testing equipment.

The sensitized material holder BI is a standard film holder with, however, certain modifications to be presently described. For the purpose of making a record test by my equipment, no modification of the film holder 5| from a standard construction is necessary.

The operation of the structure thus far described is as follows:

The sensitized material holder 58 is loaded with a sensitized sheet of paper or film and is placed in the channel of the vertical support member 22, being retained by the latch member or lever 59 until it is desired to make the test. When a test is to be made, the dark slide of the holder 58 having first been withdrawn, the said holder is released by the latch member or lever 59 and drops by gravity, and upon reaching the switch operating arm 61 the switch 25 is operated, thereby completing the circuit through cable I! to the battery case, the flash-lamp and magnetic tripper 52, thus operating the shutter II.

In order to ascertain the instant of time when the shutter II is caused to open with relation to the flash of the photoflash lamp, I have provided two openings 89, ill, in the vertical support member 22, as shown in Figs. 1, 2, 3, etc. The opening 69 is of smaller diameter than the opening 10 so as to allow a reduced amount of light to pass therethrough, thereby providing an opportunity better to record the light intensity, since, as is well known, the more light passing through the holes 89, II, the denser will be the exposure.

As the sensitized material holder 58 passes the switch operating arm 81, as previously described,

and thus causes the flashlamp to be ignited and the shutter 8| to be operated, the sensitized material 580 that is in the said holder 58 will be behind the holes 89, I0, and said holes 89, III and the shutter opening of the shutter 8| all receive light from the fiashlamp. Therefore, an unexposed area of the sensitized material 58a will appear behind the opening II, provided in the front face of the vertical support member 22, as shown in Fig. 2, and which opening II, as there shown, is aligned with the center of the opening of the shutter 8|, as indicated in Fig. 3, said sensitized material being also behind the holes 89, I0, previously referred to. That is, said opening II is in what may be termed lineof-vision register with the center of the opening of the shutter. Therefore, light is admitted to the sensitized material 58a in the holder 58. Inasmuch as the holes 89, Ill are always open, the sensitized material 58a will be exposed during all of the flash of the photoflash lamp, but light is excluded from the hole 1| by the shutter 3| at all times excepting when the shutter aperture is open, it being noted that the shutter aperture is controlled by the electromagnetic tripper 52, as previously explained.

Therefore, if a photofiash lamp is placed in the socket of the battery case and the holder 58 of suitable construction is loaded with sensitized material 580, and is placed in the vertical support member 22 and then allowed to drop by manual manipulation of the latch member or lever, a circuit is completed to the fiashlamp and the electromagnetic tripper 52, as already explained. Consequently a flash will take place and will be recorded for the full length of such iiash through the holes 89 and Ill, and during the time that the shutter is open, light will pass through the hole II to the sensitized material "a and will also be recorded.

Upon development of the sensitized material 580, the exposed areas will appear as clearly indicated in the chart Fig. 6, wherein the area behind the shutter opening II will appear as indicated at I2, and the exposed area behind the openings 88 and I will appear as indicated at I8. When the exposures do appear as in the chart Fig. 6, the shutter is in proper synchronous relation, that is, it is simultaneous in functioning with the flashlamp, as indicated at the exposure area I3 (Fig. 6).

It will be noted that the exposed area indicated at I3 in the chart Fig. 6 builds up from no exposure to a very dense exposure, and then drops down to no exposure. It is desirable to have the opening of the shutter 3| take place during that area of greatest illumination (that is, to have it occur between the broken lines a and b of the chart Fig. 6). If, however, the exposed area I2 appeared below the broken line a or above the broken line b of the chart Fig. 6, the shutter 3| would be out of synchronous relation with the flashlamp (i. e. would not be functioning simultaneously therewith). If the said exposed area I2 appeared below the line a, the shutter 3| would be operated too soon. If said exposed area I2 appeared above the line b of the chart Fig. 6, the shutter 3| would be operated toolate. The lines a and b of the chart Fig. 6 therefore represent the desirable area in which the shutter 3| should be operated. In the instance illustrated in the chart Fig. 6, the shutter 8| was operated within the said desirable area but slightly early in time, being nearer the dotted line a. This is the preferred adjustment because with use the battery of the synchronizer will become deteriorated and the synchronizer will consequently operate slightly more slowly. Therefore, as the battery voltage drops,-the exposed area I2 would move slightly upward with respect to the chart Fig. 6 if a further test were to be made.

The speed at which the sensitized material holder 58 travels downward when released is not critical, but the position along the vertical support member 22 of the switch 35 with its operating arm 81 should be such that the flashlamp willbe ignited during the time that the sensitized material 58a in the holder 58 is in position behind the holes 88', I8 and II. After such position for the location of the switch 35 along the support member 22 has once been located either by mathematical determination or by experiment, no further adjustment of parts is required for making a record test by the testing equipment herein disclosed. Since the entire duration of the flash is recorded, and since the holes 88, I0 in the support member 22 are in horizontal alignment with the-hole II, it is always an easy matter to plot the exposed area I2 against the exposed area I3, and since the entire length of the exposed area I3 never is greater than twenty-five per cent of the length of the piece of sensitized material 58a, a considerable latitude is allowable in the adjustment of the position of the switch 35. Nevertheless for best all round performance I have found that the proportions represented in the drawings of this application are the correct proportions of the vertical support member 22 with the illustrated position of the switch 35 being ideal for the testing of all flashlamps of known manufacture.

The sensitized material holder 58 is of the usual construction of sensitized photographic film holders, but with certain modifications when used for visual tests. The structure of said holder 58 is most clearly evident from Fig. 4, wherein it is represented as provided with separating plates 'Il, I5, film retaining strips I8, I8, grooves l1, 11 for receiving dark slides and the dark slides I8, I8, only one of which is shown, the other having been removed to permit exposure of sensitized material 58a in the manner previously described.

When the testing equipment herein disclosed is used for making the visual test, the holder 58 is not loaded with sensitized material, but its position is reversed as it is placed in the vertical support member 22, so that an opening I8 of the dark slide I8 of the holder (shown in Fig. 4) is in alignment with the hole II of the vertical support member 22 (that is, when the holder 58 is dropped, said opening I9 comes in line-of-vision register with the hole II of the vertical support member 22), and'the openings 88, 8| of the separating plates 15, I4 respectively (shown in Fig. 4) are in horizontal alignment with the opening I9 in dark slide I8, and are of suiiicient length to uncover holes 82 and 83, also provided in the dark slide I8. (This structure is best shown in the sectional view Fig. 13.) The said dark slide 18 is provided with the said three openings I8, 82, 83. The opening 82 is provided with a red filter, indicated at 84, and the opening 83 is provided with a green filter, as indicated at 85. I am not limited to the provision of filters of the 4- assasov stated colors, as any two suitably contrasting colors may be employed.

When the dark slide 18 is in position for making a visual test, the holder parts will appear as shown in Fig. 13, and when they are in position for making a record test, the holder parts will be positioned as'shown in Fig. 4.

For making a visual test, two additional holes are provided in the vertical support member 22, being indicated in Fig. 5 by dotted lines at 88, 81, and in full lines in Fig. 9, and in section in Fig. 13. When making a record test, it is necessary that the holes 88, 81 are covered or capped. For this purpose, I have provided a light valve consisting of a disk 88, best shown in Figs. 4, 5 and 9 as mounted on the vertical support member 22, and as having a handle 88 attached thereto by rivets 88, 88. The said light valve or disk 88 is provided with openings 8| and 92 for alignment with the openings 81 and 88 respectively. When the said light valve or disk 88 is in position for making a visual test, it will be precisely as indicated in Fig. 9. The said light valve or disk 88 is held in place by a ring 88 concentric therewith and secured to the vertical support member 22 by large headed screws 88, 88. The said concentrically arranged ring 88 is provided with a flange 88 having an opening into which is fitted the said light valve or disk 88, r

The screws 88, 84 and washers 88a are provided to hold the light valve or disk 88 in position in the ring 88 and against the vertical support member 22.

When the said light valve or disk 88 is turned in a clockwise direction viewing Figs. 5 and 9, the handle 88 travels in a slot provided therefor in the ring 83. The openings 8| and 82 will thus be moved out of alignment with the openings 88, 81, and thereby all light is prevented from passing through the holes 88, 81, and reaching the sensitized material 880 in the holder 88. The light valve or disk 88 is in this position when making a record test, and when its handle 88 is moved in a contraclockwise direction viewing Figs. 5 and 9, the hole 8| of the light valve or disk 88 will be in alignment (that is, in line-ofvision register) with the hole 81. The parts will then be in the position shown in Fig. 9, which is the position of the parts when making a visual test. Inasmuch as the openings 88 and 8| of the separating plates 18, 18 will be in alignment with the hole 1| and the holes 88, 81, light can pass through the sensitized material holder 88 and through the vertical support member 22 and the disk 88 when the said sensitized material holder 88 reaches the position shown in Fig. 13, and also through the shutter 8| when such shutter is open.

In order to provide a fixed source of illumination for use when making a visual test, the vertical support member 22 has attached thereto a supplemental support member 88 by means of rivets 81, 81', best shown in Fig. 11, and also in Figs. 1 and 2, said support member 88 having a suitable formation 88 to which is hung, as shown in Fig. 11 a flashlamp 88 by means of a bale I88. The flashlamp 88 is of the structure shown in Fig. 11, and is the standard flashlamp as carried by armed forces of the United States, said flashlamp functioning in the usual way. It is of the right angle type and is so positioned that the holes 88, 81 and 1| will be illuminated when the battery case of said flashlamp 88 is in place and the switch 88a has been operated.

For making a visual test, the cable 81 is suitably plugged to the electromagnetic tripper 82 and to the battery case, and the switch 88 is connected to the battery case. When the sensitised material holder 88 is released in the manner previously described, the shutter 8| will be operated as previously set forth.

In order to make a visual test, the light valve or disk 88 is set in the position shown in l 'ig. 8 and the sensitized material holder 88 is placed in the position shown in Fig. 10. When such holder 88 is placed in the vertical support member 22, in the position indicated in Figs. 10 and 11, and is allowed to drop by releasing the latch member or lever 88, the electromagnetic tripper 82 will be operated when the said holder 88 reaches the switch operating arm 81, so completing the circuit to the battery, and to the electromagnetic tripper 82 through the cable 81, the flashlamp 88 having previously been illuminated manually in the usual manner. The shutter 8| will be caused to open by the completion of the circuit as stated. and the operator will see the light from the flashlight 88 projected through the openings 88, 81 if the shutter is in proper synchronous relation with the fiashlamp.

If light is visible onhr through holes 81 and 1|, the synchronizer has been adjusted to function too early for the best results, and if light is seen only through holes II and 88, the synchronizer has been adjusted to function too late for the best results. The synchronizer tripper should then be adjusted so that light will be visible through all three openings 81, 1| and 88.

The filters 88, 88 are provided in order that the operator may determine through what holes the light passes. When a start is made on adjusting the synchronizer by beginning the visible test now being described, it is very likely that the adjustment of the synchronizer will be found to be far from correct. Therefore, at the beginning of the test of the synchronizer, it is probable or possible that the operator may see light through one hole only, and if light that he sees is green, he will know that the position of the synchronizer has been improperly set for too late functioning. If, on the contrary, the operator sees only. a red light, he will know that the positioning oi the synchronizer is too early. If he sees a green light and a white light, he will know that the positioning of the synchronizer is close to the correct position, but is still too late, and if he sees a white lightand a red light, he will know that the positioning of the synchronizer is early but very close. All that is necessary is for the operator to make adjustment in the proper direction so that he will see both a red light and a green light, and of course when he sees them, he will also see a white light. He will then know that the synchronizer being tested is in a positiogn of correct adjustment for proper function- When using the visual synchronizer test, it is important that the switch 88 be in proper position with respect to the sensitized material holder 88 when contact is made at the switch 88, so that there will be a proper time delay between the time of contact and that instant when the openings 88, 82 of the said sensitized material holder 88 are in alignment (that is. in lineof-vision register) with the openings 81, 88 of the vertical support member 22. This can be readily checked when using the synchronizer test as a recording test. It is only necessary to adjust the -synchronizer switch 88 and its operating arm 61 in a vertical direction, so that the flash takes place at a proper instant of time with respect to the opening ll. After this adjustment has once been made for a flash bulb of given manufacture (that is to say, for a flash bulb known to have a certain time delay, such, for example, as twenty milliseconds), all tests can be then made without further adjustments so long as flashlamps having that time delay are used with the synchronizer that is being tested.

The synchronizer testing equipment herein disclosed is flrst adjusted by making a record exposure and the position of the switch 35 is adjusted in a vertical direction along one side of the vertical support member 22, so that the flash as indicated by the exposed area 12 is located between the dotted lines a and b of the chart Fig. 6. The position of the switch 35 with respect to the position of the sensitized material holder 58 at the time contact is made will then be correct for making a visual reading when testing lamps known to have the same time lag or delay. If it is desired to test a lamp having a known different time lag or delay, the switch 35 must be moved along and readjusted on the vertical support'member 22 until the exposed area 12 will be between the lines a and b, of the chart Fig. 6. If the flashlamp being tested is of a different characteristic than the one illustrated in the chart Fig. 6, by which is meant a flashlamp having a longer duration of flash or a shorter duration of flash, the space between the dotted lines a and b must be increased or decreased accordingly, and of course it will be necessary to adjust the position of the switch 35, so that the flash, as indicated by the exposed area 12 will be between the repositioned two lines a and b. Since the holes 69, I and H on the vertical support member 22, through which light passes, are in horizontal alignment, when the shutter tripper is once adjusted for making a record test, the exposed areas 12 and 13 will always be as indicated in the chart Fig. 6.

The synchronizer testing equipment herein disclosed is desirably of such construction that it can readily be folded for transportation or storage. To that end the base member 2| is provided with two elongated slots |0I and I02 along the opposite lateral edges thereof, as indicated in Fig. 1. The said vertical support member 22 may be detached from the base member 2| by loosening screws 23, 23, and the vertical member 22 can be slid into the said parallel slots llll, I92, after having been removed from the base member 2|. Attached to the screws 23, 23 are rubber bumpers I94, I04 to absorb shock when the sensitized material holder 58 reaches the limit of its downward travel following its release by movement of the latching means or lever 59.

A resume of the operation of the disclosed synchronizer testing equipment is as follows.

The vertical support member 22 is first withdrawn from the parallel slots |0|, I02 of the base member 2| and secured in the position shown in Fig. 1. A flashlamp battery case is then mounted in suitable position on the base member 2|. The lens board 30 having mounted thereon a shutter 3| and lens 32 is then placed in position in the lens board carrier 28 and is securely held thereto by means of the springs 33, 33. The necessary plugs of the circuit wiring are inserted.

The sensitized material holder 58 is loaded with a sheet of sensitized material 58a, it being understood that the entire apparatus is in a photographic dark room in the fleld or other place of use. A flashlamp or bulb is placed in the socket of thebattery case, the shutter 3| is set for the desired shutter speed, and the sensitized material holder 59 is allowed to drop by the releasing action of the lever 69 constituting the latching means. When the said sensitized material holder 58 reaches the contact spring 61, a circuit is completed, thus causing the flashlamp to be ignited and the electromagnetic tripper 52 to be operated in the manner previously described. The shutter 3| will then be caused to be opened and the sensitized material 58a will be in position behind the holes 69, 10, H in the vertical support member 22, thus exposing the sensitized material 59a and upon development thereof it will appear as shown in the chart Fig. 6 if the tripper is properly adjusted.

If the exposed area 12 is below the line a of the chart Fig. 6, it will be necessary to adjust the electromagnetic tripper 52 so that the said shutter 3| will be operated relatively later than when the described test was made. If the exposed area is above the dotted line b of the chart Fig. 6, the electromagnetic tripper 52 must be adjusted to cause the hash to occur relatively earlier than in the described test. When a proper adjustment has been found and the sensitized material 58a is developed, the latter will appear as shown in the chart Fig. 6, where the exposed area. 12 will be located between the dotted lines a and b of the chart Fig. 6.

In order to make a visual test, the sensitized material holder 59 is reversed in position, but is held from dropping by the latch member or lever 59, the flashlamp 99 is hooked onto the flashlamp support 96, and the switch 99a is operated in usual manner to cause the flashlamp 99 to be illuminated. Said sensitized material holder 58 is then released by pressing upon the pad 60 of the latch member or lever 59, whereupon said holder 58 drops. As the shutter 3| is operated in the manner previously described, one or more of the holes 81, II and 86 will be illuminated and the electromagnetic tripper 52 is ad usted to cause the said shutter to be operated either later or earlier depending on which holes are illuminated, until an adjustment is reached where all three holes 91, 'H and 86 are illuminated as described. The operator will then see a green light and a red light with a white light between them.

The battery case is usually laid flatwise on the horizontal base member 2| when making a visual test rather than positioning it upright in the hole or other support provided therefor, so as thus to provide a clear path for the operator to view the holes 81, H and 86 through the lens 32.

The synchronizer tester equipment herein disclosed can be used both for making recorded tests and visual tests. This is very desirable because at times the adjustment is made by someone other than the operator of the camera, and it is very desirable that the operator of the camera have at his disposal the record of the performance of his synchronizer equipment. It is, however, necessary to use at least one flashlamp when making the record test. The visual test method is used for quick checking upon the performance of the synchronizer equipment, and it is also used when a record test is to be made. The usual procedure is to adjust the synchronizer as accurately as possible by the visual method and then to make a record test. In this way it is necessary to use only one flashlamp.

Actually, in the experimental work and in the designing and building and testing or the qu pment herein disclosed, it was necessary to than a great many lamps in order accurately to ascertain the correct position for the switch fl. Aiter such correct position for the switch II has once been found, additional apparatus can be manuiactured from fixed measurements, since the velocity of the sensitised material holder ll remains constant enough !or all practical purposes. Therefore, it is never necessary for the ope r or the disclosed equipment to use more than one flash bulb in adjusting any one synchronizer, inasmuch as he first proceeds to make his adjustment by the visual method, and when all three holes (that is, the red, the white and the green holes) are seen when making the visual test, the record test which follows will be that shown in the chart Fig. 6, and it is only necessary to make the recorded test when the record oi. that test is to be used for future reference.

I am aware that heretofore there has been provided an equipment having visual testing means for photoflash synchronizers, but so iar as I am aware I am the first to provide a testing equipment for photographic flashlight synchronizers by which a visual test can be made and by which a record test can also be made, and so far as I am aware a sensitized material holder or carrier has never been used-in the manner and for the purpose herein disclosed.

Having thus described one illustrative embodiment of the invention herein claimed, it is to be understood that although specific terms are employed, they areused in a generic and descriptive sense and not for purposes of limitation, the scope of the invention being set forth in the following claims.

I claim:

1. As a new article of manufacture for use in a testing equipment for photographic flashlight synchronization, a sensitized material holder adapted to be temporarily supported in said equipment and then dropp d past light-admission openings in an upright wall 01 said equipment, said holder having at one side means for receiving sensitized material and at such side having means for receiving a dark slide for covering such sensitized material when in the holder and having at the other side a dark slide having therein at least two adjacent through-openings in substantially vertical alignment, said openings having difierent light transmitting characteristics, whereby to determine through which of said dark slide openings light is transmitted in making a visual test, while said holder is dropping past a light-admission opening or said equipment and the open shutter, said holder also having a separating plate provided with an opening therein which is elongated sufiiciently to expose both of the said openings in the dark slide, and which is in alignment with said openings in the dark slide.

2. As a new article of manufacture for use in a testing equipment for photographic flashlight synchronization, a sensitized material holder adapted to be temporarily supported in said equipment and then dropped past light-admission openings in an upright wall of said equipment, said holder having means at one side to support therein a sheet of sensitized material, and having at the other side a dark slide ll provided with a small opening ll therein, and having two separating plates ll, 14 respectively provided with small openings iii, ll, both in alignment with the said opening ll 0! the dark slide II. the said dark slide also having small openings 82, It, in vertical alignment with said opening II in said dark slide and close thereto, said openings 80, ll being large enough to cover all of said openings II, l2, N of the dark slide, said slide openings having diiierent light-transmitting characteristics, whereby to determine through which of said slide openings light is transmitted in making a visual test, whereby a record test can be made when a sheet of sensitized material is positioned in the holder at the first mentioned side and said holder is dropped in said equipment, and whereby a visual test can be made without the use of a sheet of sensitised material in the holder, by reversing, side for side, the position or the holder as supported for dropping in the equipment, with respect to the position 01' said holder in the equipment when supported therein ior a record test.

3. As a new article oi manufacture for use in a testing equipment for photographic fisshlight synchronization, a sensitized material holder adapted to be temporarily supported in said equipment and then dropped past light-admission openings in an upright wall of said equipment and past a supported shutter, said holder having at one side means for receiving sensitized material and at such side having means for receiving a dark slide for covering such sensitized material when in the holder and having at the other side a dark slide having therein at least two adjacent through-openings in substantially vertical alignment and having different light transmitting characteristics, said holder being of a shape permitting it to be reversed side for side in said equipment for a record test and a visual test respectively, so that a record test can be made with a sheet of sensitized material positioned in the holder at the first-mentioned side, and a visual test can be made without a sheet oi sensitized material in the holder, but with the holder reversed, side for side, in said equipment, from the position said holder occupied in such equipment when used for such record test therein.

4. A duplex sensitized-material holder for a testing equipment for photographic flashlamp synchronization, adapted to receive at one side sensitized material for use in making a record test by dropping said holder past an exposure opening of said equipment, said sensitized material holder having at the other side a dark slide with two adjacent openings spaced lengthwise of the slide for admitting light in making a visual test in such testing equipment, said holder also having separating plates II, 14 provided respectively with openings II, I each in substantial register with the said two openings of the dark slide, and means associated with said holder for determining through which of said slide openings light is transmitted in making a visual test.

5. A duplex sensitized-material holder for a testing equipment for a photographic fiashlamp synchronizer, adapted to receive at one side sensitized material for use in making a record test by dropping said holder ast an exposure opening of said equipment, said sensitized material holder having at the other side a dark slide with an opening I! for admitting light in making a visual test in such testing equipment, said holder also having separating plates 1', 14 provided respectively with aligned openings ll. 0 I, the said dark slide also having vertically displaced openings 82, 88, vertically displaced horn and adia cent the slide opening l5, each or the openings 88, 8| being aligned with the said three openings l8, c2, 83 said derl: slide, and means associated said holder for determining through which said slide openings light is transmitted in making a visual test.

6. As a new article of manufacture for use in a testing equipment for photographic flashlight synchronization, a sensitized material holder adapted to be temporarily supported in said equipment and then dropped past light-admission openings in an upright wall of said equipmen-t, said holder having at one side means for receiving sensitized material and at such side having means for receiving a dark slide for covering such sensitized material when in the holder and having at the other side a dark slide having therein at least two adjacent throughopenings in substantially vertical alignment for admitting light while said holder is dropping past a light-admission opening of said equipment and the open shutter, there being means associated with said holder for determining through which of said slide openings light is transmitted in making a visual test.

7. A sensitized-material holder for use in a testing equipment for photographic flashlamp synchronization, said holder having at one side means for receiving sensitized material and 'at such side having means for receiving a. dark slide for covering such sensitized material when in the holder and having at the other side a dark slide having therein three openings 83, I8, 82 in substantial alignment lengthwise of said dark slide and in sufiicient proximity to each other to be within the area of the opening of the shutter that is being tested in the equipment, and past which shutter the holder is dropped in the equipment in such visual testing operation, said slide openings having different light-transmitting characteristics, whereby to determine through which of said slide openings light is transmitted in making a visual test.

8. A sensitized-material holder for use in a testing equipment for photographic fiashlamp synchronizatiomsaid holder having at one side means for receiving sensitized material and at such side having means for receiving a dark slide for covering such sensitized material when in the holder and having at the other side a dark slide having therein at least two vertically displaced through openings that, in the dropping of said holder in the testing equipment in making a visual test, may be brought into line-ofvision register with an opening in the equipment and a registering opening of the shutter that is being tested in said equipment, said holder havtesting equipment for photographic flashlamp synchronization, said holder having at one side means for receiving sensitized material and at such side having means for receiving a dark slide for covering such sensitized material when the holder and having at the other side a dark slide having therein three openings 83, i8, 82 substantial alignment lengthwise of said darl: slide and sumcient proximity to each other to he within the area oi the opening of the shutter that is being tested the equipment, and past which shutter the holder is dropped in the equip ment in effecting a visual testing operation, and contrasting filters over two of said three openings.

10, A sensitized-material holder for use in a testing equipment for photographic flashlamp synchronization, said holder having at one side means for receiving sensitized material and at such side having means for receiving a dark slide for covering such sensitized material when in the holder and having at the other side a dark slide having therein upper, middle and lower openings 88, I9, 82 in substantial alignment lengthwise of said dark slide and in sufiicient proximity to each other to be within the area of the opening of the shutter that is being tested in the equipment, and past which shutter the holder is dropped in the equipment in effecting a visual testing operation, and contrasting filters over the upper and lower openings 83 and 82.

11. A sensitized-material holder for use in a testng equipment for photographic flashlamp synchronization, said holder having at one side means for receiving sensitized material and at such side having means for receiving a dark slide for covering such sensitized material when in the holder and having at the other side a dark slide having therein upper, middle and lower openings 83, I9, 82 in substantial alignment lengthwise of said darkslide and in sumcient proximity to each other to be within the area of the opening of the shutter that is being tested in the equipment, and past which shutter the holder is dropped in the equipment in effecting a visual testing operation, said slide openings having different light-transmitting characteristics, whereby to determine through which of said slide openings light is transmitted in making a visual test, said holder having two separating plates each having an opening therethrough in substantial register with each other and in substantial register with said three openings 83, I9, and 82.

12. A sensitized-material holder for use in a testing equipment for photographic flashlamp synchronization, said holder having at one side means for receiving sensitized material and at such side having means for receiving a. dark slide for covering such sensitized material when in the holder and having at the other side a dark slide having therein upper, middle and lower openings 83, 19, 82 in substantial alignment lengthwise of sa'd dark slide and in sufllcient proximity to each other to be within the area of the opening of the shutter that is being tested in the equipment, and past which shutter the holder is dropped in the equipment in effecting a visual testing operation, and contrasting filters over the openings 83 and 82, the middle opening 18 being an unfiltered opening.

JOSEPH A. SPRAGUE. 

